The present invention relates to a reinforced veneer and a method of reinforcing a veneer sheet cut from a imperfect log.
A veneer sheet cut from an imperfect log is found to have split portions. Due to the veneer sheet being thin, such splits are apt to develop during plywood manufacturing. If such splitting occurs excessively, alignment prior to the plywood manufacturing process becomes difficult.
Conventional methods proposed to overcome the problem in handling a weak or split veneer sheet include a method in which a tape is pasted on abutting ends of two adjoining veneer sheets (U.S. Patent Office Defensive Publication T 896,014), a method in which adhesive impregnated strands are pressed onto trained veneer sheets to join them (U.S. Pat. No. 4,042,440) or a method in which a veneer sheet is provided on its surface with inclined grooves or slits in which strings are imbedded and fastened by adhesive (U.S. Pat. No. 4,044,182). The first two methods are based on bond strength between the veneer sheets and the adhesive, and bond strength between the adhesive and the binder such as a tape, a strand, or the like.
It is, however, often found that the bonding strength between the veneer sheets and the adhesive is affected by humidity, surface quality, or grain condition of the sheet so that sufficient joining or reinforcing cannot be obtained.
The third method has a disadvantage in that, the forming of slits on the surface, sacrifices the strength of each veneer strip to connect a plurality of strips.